过去式和过去分词 有什么分别？

动词有四种形式：原型、过去式、过去分词和现在分词

过去式组成一般过去时
I finished my homework just now.

过去分词组成各种完成时态，构成分词结构以及表示被动语态
I have finished my homework now.
I had finished my homework when my mother came back home.
He came back home after fired by his boss.
He was fired by his boss.

过去式是指过去已经做过，现在已经完成的动作，而过去分词是组成各种完成时态，构成分词结构以及表示被动语态！！

动词的过去式和过去分词变法是一样的，除了几个特殊的以外。（对一起，我这一阵有事，详细的我明天给你说）